著者

長谷川 恵一 安藤 清 北出 正司 坂本 光正 福島 幸夫 沖田 耕一

出版者

一般社団法人日本機械学会

雑誌

日本機械学会論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.61, no.588, pp.1713-1718, 1995-08-25

参考文献数

8

被引用文献数

2

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The LE-7 rocket engine main injector has undergone a few occurrences of welded joint structural failure because it is subjected to high thermal stress during the engine start and stop sequence. The low-cycle fatigue test and high-strain fatigue test which were conducted as part of failure analysis revealed that the welded joint has a considerably shorter fatigue life than expected. To improve the ductility and toughness of the welded joint, high-temperature-solution heat treatment was applied after welding. The low-cycle fatigue life of a welded joint subjected to this solution heat treatment became three times longer than that without it. A design criterion was established for low-cycle fatigue life estimation, and the life requirement was found to be satisfied.

著者

藤田 祥子 尾上 雅人 浅野 明雄 佐藤 良一

出版者

一般社団法人日本機械学会

雑誌

日本機械学会論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.63, no.606, pp.335-340, 1997-02-25

参考文献数

8

被引用文献数

1

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Stresses and stiffnesses of band adhesive box section beams subjected to torsional loads have been studied analytically. The influences of pitches and width and thickness of the adhesives on the stress distributions and the torsional rigidities were investigated analytically and numerically. Maximum shear stress in the adhcsives occurs at an intersection of the adhered boundary and the inner edge of flange, and it decreases with increase in the width and thickness of the adhesives. The analytical results were consistent with the results of finite element methods.

著者

中 庸行 山本 /和人 磯野 吉正 田中 武司 寺山 暢之

出版者

一般社団法人日本機械学会

雑誌

日本機械学会論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.66, no.644, pp.698-705, 2000-04-25

参考文献数

17

被引用文献数

2 5

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This paper describes the evaluation of adhesion strength between the amorphous Silicon carbide (a-SiC) thin film, Diamond-Like Carbon (DLC)/a-SiC laminated thin film and materials used for the cutting tool. The a-SiC and DLC/a-SiC thin films were deposited on the tungsten carbide steel substrate:K10 and on the high speed steel substrate;SKH51 by Plasma-Enhanced CVD method of the hot cathode PIG discharge type. Scratch tests were carried out for examining the critical fracture load of the films. Finite Element Method (FEM) analyses were also performed to clarify the stress distribution at the interface between the films and substrates. The stress intensity factors K<SUB>I</SUB> and K<SUB>II</SUB>and the fracture toughness K<SUB>C</SUB> were calculated from results of scratch tests and FEM analyses. The K<SUB>I</SUB>, K<SUB>II</SUB>and K<SUB>C</SUB> of a-SiC and DLC/a-SiC thin films deposited on the K10 substrate were larger than those of the thin films deposited on the SKH51 substrate. The K<SUB>I</SUB>, K<SUB>II</SUB> and K<SUB>C</SUB> of both of the films were directly proportional to the density of a-SiC thin films. In turning experiments, the delamination area of DLC/a-SiC thin films deposited on the cutting tool of K10 is closely related to the K<SUB>C</SUB> obtained from the scratch tests and FEM analyses.

著者

中 庸行 磯野 吉正 田中 武司 寺山 暢之

出版者

一般社団法人日本機械学会

雑誌

日本機械学会論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.65, no.634, pp.1427-1434, 1999-06-25

参考文献数

15

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This paper describes the microstructural effect of Diamond-Like Carbon (DLC) thin film on micro-tribological properties. DLC thin films with density of 1.9-2.4 g/cm<SUP>3</SUP> were deposited on Silicon (111) surface by Plasma-Enhanced CVD method of the hot cathode PIG discharge type. The effect of deposition conditions on the microstructure of DLC thin film was evaluated by Raman spectroscopy. Increasing the bias voltage and the discharge current shifted the peak of the G-band shift toward high frequency and enlarged I (D)/I (G) ratio. Pin-on-Plate friction experiments were carried out using a diamond pin in high vacuum. The friction coefficients of DLC thin films indicated constant values during the friction. The friction coefficients increased with shifting G-band toward low frequency in the range above 1540 cm<SUP>-1</SUP>, but those did not vary with increasing I (D)/I (G). The friction coefficients were directly proportional to density of the film. Molecular orbital calculations revealed that the adhesion energy on the sp<SUP>3</SUP> bonding atom cluster was higher than that on the sp<SUP>2</SUP> bonding atom cluster.

著者

松井 勝幸 衛藤 洋仁 雪竹 克也 三阪 佳孝 安藤 柱

出版者

一般社団法人日本機械学会

雑誌

日本機械学会論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.66, no.650, pp.1878-1885, 2000-10-25

参考文献数

13

被引用文献数

9 11

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The surface refining method is a useful technique to improve the fatigue limit of gears. One of the methods is the Carburizing Method. To increase the fatigue limit of the Carburized gears, the following five techniques need to be developed:a)Reduce abnormal surface structure. b)Obtain a fine grain size. c) Decrease the retained Austenitic structure. d)Increase hardness under the surface. e)Improve the residual stress distribution under the surface. For this purpose, the authors conducted a study by using DSG1 steel gears on the new compound surface refining method consisting of Vacuum Carburizing, Contour Induction Hardening and Double Shot Peening. The results showed that the fatigue limit of the gears processed by the new compound surface refining method achieved 125% better than that of the conventional Vacuum Carburized gears.

著者

鈴木 秀人 松村 亜紀子 福永 久雄 原口 忠男

出版者

一般社団法人日本機械学会

雑誌

日本機械学会論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.62, no.603, pp.2501-2505, 1996-11-25

参考文献数

15

被引用文献数

9

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Influences of the recycling process on the fatigue crack propagation (FCP) property of glass fiber-reinforced PEEK were examined. In the present research the influence of the recycling process on the property of matrix resin was focused on. The main results were as follows: (1)It was noted that the FCP property of recycled PEEK/GF materials were as superior to that of virgin material. (2)The length of glass fibers in PEEK resin as not markedly reduced during the recycling process, due to the good fluidity of PEEK resin. (3)FCP curves on a da/dN-&Delta;K diagram for virgin and recycled PEEK/GF materials were expressed as one curved line on a da/dN-&Delta;K/E diagram. It was found that the elasticity modulus had been improved by repeated melting and crystallization during the recycling process.

著者

塩澤 和章 小林 弘和 寺田 正夫 松井 明

出版者

社団法人日本機械学会

雑誌

日本機械学会論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.67, no.662, pp.1639-1646, 2001-10-25

参考文献数

12

被引用文献数

2 2 1

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As a study in a series to investigate the effect of anodized coating on fatigue strength of aluminum alloys, repeated tensile fatigue test was conducted in laboratory air and at room temperature under the stress ratio of 0.01 using smooth plate specimen of A2014-T6 and A6151-T6 with anodized film thickness of 3&mu;m. Fatigue strength of the anodized specimens decreased by 20-30% as compared with those of uncoated one. Decrease of fatigue strength depended on static strength of the tested materials. The fracture of anodized coating film occurred at the critical strain formed by the accumulation of plastic deformation of substrate metal at an early stage of repeated tensile fatigue process and crack was induced in the substrate at the flaw of the anodized film. It was recognized that fatigue life of anodized specimens was quantitatively evaluated by the consideration of cyclic stress-strain response and strain-life fatigue behavior.

著者

中川 博文 北村 純一 近藤 徹 飯沼 和三 高橋 賞

出版者

一般社団法人日本機械学会

雑誌

日本機械学会論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.61, no.582, pp.466-471, 1995-02-25

被引用文献数

4

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The efficiency of visual biofeedback (VFB) training method using a Photoelastic imaging system on restoring and stabilizing a standing position of stroke patients was investigated. As a stroke group, seven hemiplegics were selected with the mean of 57 year-old. Twelve age-matched healthy subjects were selected as controls. The subjects were asked to stand upright on the photoelastic apparatus and to gaze at a marker 1.5M distant on the wall. Then, VFB training was performed for ten minutes by self recognition of his own pressure patterns which were produced by photoelastic system and were monitored on a TV screen. The patterns were photographed in each different condition such as in a standing position with eyes open or closed before and after l0-minute-training with VFB, and were comparatively analysed. The results showed that (1) the ratio of affected side to unaffected definded by the number of first fringes produced increased significantly after VFB up to the control level, (2) the ratio of body weight loading on the affected side to unaffected was significantly increased after VFB, and (3) the position of center of contact pressure on the longitudinal axis of an affected sole was found to be significantly more posteriorly sifted than in the control and was remained unchanged after VFB. In conclusion, the VFB method using a photoelastic imaging system may be useful to enhance visual-contact motor balancing functions in patients with hemiplegics and also to study a restoring process of neurological impairment leading to a postural problem.

著者

村上 敬宜 堤 一也 藤嶋 正博

出版者

一般社団法人日本機械学会

雑誌

日本機械学会論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.62, no.597, pp.1124-1131, 1996-05-25

被引用文献数

15 19

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In order to investigate the effect of surface roughness on the fatigue strength, fatigue tests for maraging steel which was subjected to aging treatment and was free of residual stress, were carried out. As an artificial surface roughness, extremely shallow periodical notches with notch radii P=0 and 200μm, and notch depths a=12, 22, 40 and 65μm were introduced. In addition to the effect of surface roughness, the effect of nonmetallic inclusions was also considered. The equivalent defect size (√(area<SUB>R</SUB>)) which controls the fatigue limit of specimen containing the surface roughness is defined by the function of depth and Pitch of the roughness. The lower bound of the fatigue limit for various levels of roughness can be predicted by substituting the equivalent maximum defect size (√(area<SUB>m</SUB>axt)) to the √(area) parameter model. The value of √(area<SUB>m</SUB>axt) can be evaluated by considering the interaction effect between the maximum inclusion size and roughness. The predicted values were examined by experiments and it is shown that the method of prediction is available for practical applications.